First time posting here so please don't hit me if this is in the wrong area. I am helping my daughter create a costume that needs a small LED display (matrix?) that can show an emoticon. Below is a picture of the actual character. Since a hovering display is not feasible. we are looking to put an LED display behind the mask and have it shine through. Upon researching this project a lot of roads point to Arduino to handle this. One of the problems I have ran into though is most LED displays are wide instead of tall, and I understand why. 2 things I am looking for this to do. I will need it to display not only a "0" but also emoticons such as

:) :( :/ and so on.My second need is to be able to have a button (or other method of input) that I can press and it will go to the next emoticon, or random. The displays I have seen are constantly scrolling. Any help pointing me in the right direction would be greatly appreciated.

I think your best bet would be an 8x8 LED matrix. They are available in an assortment of sizes from 0.8" to 2.3" square.

You might also like the LOL (Lots of LEDs) Shield. It has a 14x9 matrix.

It sounds like the 14x9 might be the best option. So my next question would be if that can be used 14 high and 9 wide with a static emoticon and if so is there a way to trigger a change whenever I want?

Go with 4 emoticons, each assigned to a button, 4 buttons. Or I believe you can set your program to react according to how long the button presses were held in for.So one button with a quick press, press and hold for 2 secs, 3 secs, etc.

Whether the width of the display is horizontal or turned vertical; I don't think that is going to pose any problems with your emoticon other than size.

There are more than 12 emoticons but we are trying to limit it to 12 only. Even if the button just cycles to the next one. Is this feasible the the Arduino? I am trying to find out before I purchase anything.

There are more than 12 emoticons but we are trying to limit it to 12 only. Even if the button just cycles to the next one. Is this feasible the the Arduino? I am trying to find out before I purchase anything.

This is quite feasible. However, you aren't limited to that.

The main limitation on how complex the input can be will be the total I/O pins, as you'll need some pins reserved as outputs for your LED matrix. With one or more buttons you could do as you describe; have some sort binary code where pressing one to four buttons simultaneously picks a specific emoticon; or, depending on which Arduino board you are using, you might have enough pins for each emoticon to have it's own button. With a different input device, like a rotary encoder, you could use much more than tweleve emoticons with just a couple of input pins. The only potential drawback is that even a relatively inexpensive rotary encoder will probably cost a bit more than twelve common push-buttons.

There really are a multitude of different input options available, check out the mechanical inputs section of the Playground for some ideas.

Eh, Don't worry about jumping in too deep. I started using the Arduino to build a self contained 4 axis camera control rig. I still don't know anywhere near enough to do that but I am learning. If you are not on a major time limit, just go out and pick up an Arduino Uno and a starter kit and just start small, blink led, blink with delay, push on push off led ect... Then slowly start expanding what you can do.

I've been with it for a few weeks and although most of my 'projects' are trivial, I'm learning a lot more about the language, hardware and how to reach my goal.If budget is an issue there are some great Arduino clones and just order mass part kits from overseas, very cheap.

If time is the issue I'd just pick up an Uno and buy the 14x9 LED shield as suggested above, start watching I2C tutorials and matrix display tutorials, get it to do some basic stuff and come back to this fine community for further assistance.

Be warned though, once you start understanding the Arduino, you'll be hooked, soon everything is an Arduino project.

I wish you the best of luck, although my knowledge is limited I'd be happy to help any way I can once you are on your way.

Any fool can criticize, condemn and complain - and most fools do. ~ Benjamin Franklin

I really appreciate all the help and input, I really do, but I am still rather confused. Maybe I am jumping in too deep. My skills are basic soldering and PC assembly. I still feel very lost.

As smit6089 stated, it don't get discouraged!

Since there are a lot of options as far as controlling the display, I think the best next step is to talk with your daughter and decide what would be her preference. Once that is decided, the only other major factor is getting the parts so you can finish the custome before Halloween. Both the actual programming and construction should be relatively quick, but if you don't have most of a day (like on a weekend) plan on spending at an hour or two on this project for a few days before the costume is needed.

Eh, Don't worry about jumping in too deep. I started using the Arduino to build a self contained 4 axis camera control rig. I still don't know anywhere near enough to do that but I am learning. If you are not on a major time limit, just go out and pick up an Arduino Uno and a starter kit and just start small, blink led, blink with delay, push on push off led ect... Then slowly start expanding what you can do.

I wouldn't say there is only one. However, I've had good experiences with products from both Adafruit and Sparkfun, and they both have starter kits (check the links). There's also the official and still fairly new Arduino Starter Kit, though you'd probably want to buy it from a North American distributor (e.g. Adafruit sells them).

By the way, did you get what you wanted accomplished on the costume in time for Halloween?

Looks like adafruit has them in stock: http://www.adafruit.com/products/274 $19.95

You'll need an Arduino to drive it. You can mount it directly on an Arduino UNO (or older Duemilanove or Diecimila). If you want to save space in the helmet you can run 12 wires from the shield to a smaller Arduino like the Nano.

You can use this spreadsheet to design emoticons:http://jimmieprodgers.com/wp-content/uploads/2009/12/LOL-Shield-Animation-Template.ods It's set up for 14 wide and 9 tall so you may need to design your emoticons sideways.

Each frame (emoticon) will take 18 bytes so you have room for hundreds in FLASH.

The shield doesn't use any of the analog input pins and those pins can also be used for digital input or output. That gives you six direct input buttons that you can use in combinations to select from 64 different emoticons.

Looks like adafruit has them in stock: http://www.adafruit.com/products/274 $19.95

The other information was great johnwasser, but a LoL shield could be a bit bulky for the look this costume is trying to achieve. A smaller and slightly cheaper alternatives would be Adafruit's 8x8 LED matrix, $11.95. It's also Arduino compatible. Here's a link to Adafruit's tutorial for that one.